Roger Federer and Victoria Azarenka headline Day 10 action at the U.S. Open, with both vying for a spot in the final four. Meanwhile, No. 2 Simona Halep and No. 5 Stan Wawrinka also play to advance to the semifinals. Matches begin at 11 a.m. ET on WatchESPN and coverage on ESPN begins 1 p.m. ET. Check out the full television and broadcast schedule here. Full order of play for Wednesday can be found here.

Matches and storylines to watch on Day 10

Roger Federer faces Richard Gasquet to make semis: Roger Federer needed just a single break to defeat John Isner, America’s hope for a new male singles champion at the U.S. Open since Andy Roddick in 2003. Federer proved too strong under the lights of Arthur Ashe, winning 7–6, 7–6, 7–5, including blanking the 6’10” big-serving Isner in the first set tiebreak. Federer’s next test comes against Richard Gasquet, a player who also strikes a powerful, albeit rare, one-handed backhand. And if Federer looked good against Isner, he’s likely to be even more confident against Gasquet. That’s because Federer leads their head-to-head with 14 wins to just two losses. The Swiss won their last contest earlier this year in Dubai when Gasquet retired in the second set.

​Gasquet, who upset the No. 6 Tomas Berdych in the fourth round, said to reporters in a press conference, “It was a great match for me and a big victory.” He’ll need that confidence to grab his first victory against Federer since 2011. They play in the second match on Arthur Ashe after exhibition doubles.

No. 2 Simona Halep shaky, but fighting: Halep scraped through her fourth round match against Sabine Lisicki in three sets on Sunday, fighting injuries and smashing, throwing and smacking her racket along the way. Halep’s emotion helped her pull through to a maiden U.S. Open quarterfinal. But Halep won’t be able to bet on her opponent’s suffering or play poorly when she goes up against former World No. 1 Victoria Azarenka for a semifinal spot (second match, Arthur Ashe). The Belarusian is seeded No. 20 and has two majors to her credit. She also ousted her last opponent, American Varvara Lepchenko, in straight sets. Interestingly, Halep and Azarenka haven’t faced one another since 2012, with Azarenka winning both of those matches.

“I’m a different player since then. I'm stronger mentally. I'm stronger physically,” Halep said. “Everything is different. I believe that I can win it.”

Azarenka praised Halep’s recent success at majors. “She had quite a few remarkable runs at the Grand Slams, but she's been really solid on all the WTA events. I think her game speaks for itself. She's very solid from the baseline,” she said.

Petra Kvitova looks to reach first U.S. Open semi: Petra Kvitova halted the tremendous winning streak of Great Britain’s Johanna Konta on Monday, beating her in straight sets. With the win, she reached her first U.S. Open quarterfinal. If she wants to extend her run, she’ll need to take out Italy’s Flavia Pennetta, a 2013 U.S. Open semifinalist, first (first match, Arthur Ashe).

To advance to the quarters, Pennetta beat 2012 champion Sam Stosur in straight sets. Notably, Kvitova and Pennetta have split their six matches, with the Czech winning the last match in 2012 at the Olympics.

“Flavia is a good girl, so I'm looking forward for the match. It's a long time we played each other, I think. I think she's on fire,” said Kvitova to the press after beating Konta. “She's playing well here. She beat Sam in two sets. So I think she really has to feel well.”

Stan Wawrinka plays Kevin Anderson next: Stan Wawrinka, a U.S. Open semifinalist in 2013, has two major titles to his name. If he wants to collect a third at this event, he’ll need to defeat Kevin Anderson (third match, Arthur Ashe). Anderson is in the quarters of a major for the first time after defeating Andy Murray in four sets on Monday.

​Wawrinka, meanwhile, took out American Donald Young as revenge for losing to him in 2011. The Swiss looks to set-up a showdown with compatriot and friend Federer in the final four if he should beat Anderson. But that will be tough given that Anderson has won four straight matches against Wawrinka, including their last match this year at Queen’s. The South African has four wins to three for Wawrinka, who last won in 2013.

Anderson spoke about meeting the Swiss next. “It's going to be the first time at a major. Obviously I've played him a few times now. Had some success against him the last few times we've played. Very close matches,” he said. “I played very good tennis.” Anderson added, “I know what to expect going into the match. It's just about giving myself the best opportunity and obviously trying to execute as best as I can.”